A diabetic with a history of thyroid cancer who is also struggling with a neurological disorder and gastric reflux disease, Patricia Hewitt is well aware that she's not a prime candidate for health-care coverage.

"It's a miracle that I'm upright," Hewitt says, recounting the list of prescription medications she depends on daily. "I'm really dancing on the edge."

After surviving a diabetic coma in 2001 and losing her health insurance in 2004, Hewitt, a freelance writer based in Fort Myers, Fla., found herself financially devastated. In the face of mounting prescription costs, she turned to a little-discussed option in the ongoing debate about providing health care to the un- and underinsured: prescription assistance programs (PAPs).

"I have found enough programs I financially qualify for to cover $8,500 of my $10,000 annual prescription bill," Hewitt says. "That's a lot of dollars."

Offered by major pharmaceutical companies and publicized through Web-based information clearinghouses and TV ads, PAPs have blossomed where good corporate citizenship meets good public relations. The result: Big Pharma gives free medication to patients with low incomes, quietly transforming the lives of those clued into PAPs' existence by knowledgeable physicians and service providers or through their own Internet research.

"There's an awful lot of drugs out there on PAPs," says Richard Sagall. The founder of Needymeds.com, a free, not-for-profit Web resource that connects patients to programs for 3,500-plus medications, Sagall was a physician with a family practitice in Bangor, Maine, and an interest in Web design when he heard about PAPs from a medical social worker.

"I thought it would be a good idea to get the information she had up on the Web and see what happened," he says. The response was staggering: From its humble beginnings as a thought experiment in 1997, Needymeds.com now logs 10,000 unique visitors on a typical weekday. Turns out that there are not only plenty of people who need free medication -- drug companies are lining up to give it away.

"All the major products we offer are available" through these programs, says Karissa Laur, director of patient assistance programs for pharmaceutical giant AstraZeneca. The drugmaker's first PAP, initiated in 1978, provided access to the breast cancer medicine Nolvadex. In the three decades since, the company has sponsored a number of need-based programs, including one targeted at uninsured individuals with annual incomes below $30,000. Approved patients enroll for a year at a time and contact AstraZeneca every three months for refills. "It works just like a mail-order pharmacy," Laur says.

"Pfizer has an overall belief that all Americans should have access to medicines," says Jennifer S. Alltoft, the drugmaker's vice president of marketing. In 2007, the company helped 1.1 million patients access 7.7 million prescriptions -- $800 million worth of medication at wholesale prices -- through Pfizer Helpful Answers, an umbrella of assistance programs for the impoverished and uninsured. "[The PAP] is part of our corporate culture," Alltoft says.

But as the cost of prescription drugs rises at twice the rate of inflation, companies may need more than good corporate citizenship to justify an $800 million giveaway. Pfizer reported an 18 percent drop in net income in April, and AstraZeneca's profits dipped 3 percent in the same quarter. PAP participants like Patricia Hewitt aren't guinea pigs -- neither company tracks patient outcomes. If times are hard and political momentum for national health care is building, why is the pharmaceutical industry playing Florence Nightingale?

"These programs are run separate from the business side," Laur says. "There's no direct benefit to AstraZeneca except our commitment in getting people access to medicines."

"We found that the best way to reach the uninsured are through community and grass-roots efforts," says Gary Peltier, the director of Pfizer Helpful Answers. As part of "Cover the Uninsured Week" at the end of April, he traveled to six U.S. cities to meet with patients and service providers. "We are trying to spread the word [about PAPs] to the uninsured and underinsured themselves."